Hat capable of recovering original shape and method of manufacturing the same

ABSTRACT

A hat capable of recovering the original shape and a method of manufacturing the same are provided. The hat is characterized by preparing mixtures comprising waterborne polyurethane, water, and crosslinking agent; coating synthetic fiber yarns of the hat with the mixture; curing the mixtures in a certain temperature condition in order to form a thin polyurethane film on the surface of fabric or knitted fabric for the hat. The curing reaction products by the waterborne polyurethane component implement a shape recovery of the hat after the deformation or damage due to the external force in the initial shape of the hat.

BACKGROUND

The present invention relates to a hat capable of recovering the original shape and a method of manufacturing the same, and more particularly, a hat capable of preserving the original shape of the hat as it is, and recovering the original shape of the hat even after washing or using it for a long time, and the manufacturing method of the same.

In general, hats have been developed for use on people's heads. As lifestyles diversify, these hats come in various configuration and shapes, or are manufactured via adding various functions.

The popular types of hats today are exemplified by the knitted hat, which is manufactured mainly from the process of knitting, the ball cap, which is widely known as a sports hat comprised of a crown and brim, the beret, the traditional French hat that has no brim and is known as the painter's hat, and the fedora made of waterproof cotton and a visor formed around.

Such hats basically protect the user's head and include a crown part especially to protect the user's head and to look stylish at the same time.

Today, hats are increasingly being used by both men and women, young and old, for protection from direct sunlight and the cold, and becoming fashion additionally.

When looking at these hats, focusing on the most common hats, we can classify the hats into a sewing hat manufactured by bonding fabrics of various fibers through a sewing process, and a knitted hat manufactured by a knitting apparatus using various fibers.

The shape of sewing caps is well maintained due to the characteristics of the fabric used and the seam line. An example of the sewing caps is a sports hat. However, the sewing caps have insufficient ventilation, so a design to compensate it is frequently required, and the labor cost is often significant in the manufacturing cost.

On the other hand, knitted caps are manufactured with various fibers using an automated knitting device, and have a characteristic that most of them consist of a crown for a user's head.

Since the knitted hat forms a part corresponding to the crown portion with a knitted fabric, it has excellent ventilation, but generally has a disadvantage that it is not strong enough to maintain the shape of the hat. If the hat's shape change occurs while the hat's user is using the hat, it can be regarded as the user's negligence and can be attributed to the user's responsibility. It also occurred frequently during the transportation. During the distribution process from the manufacturing plant to the sales site, if it cannot withstand the external force applied from the outside, it is crushed or deformed from its original shape and it has the damage that cannot be recovered to its original shape.

In order to overcome this disadvantage, a method of manufacturing a hat by spraying a knitted cap with starches, fixing the knit cap to a predetermined wooden frame to make a shape of the hat, and drying the hat in the shade at room temperature has emerged (Registered Korean Patent No. 10-0661283. Since this method uses wheat paste, rubber paste, or glutinous rice paste, etc., when the cap is used for the first time, the original shape is maintained, but as time passes, there is a disadvantage of limited persistence for the original paste, being disintegrated and disappeared or lost by sweat.

In addition, in order to solve the disadvantages of the knitted cap, a knitted cap using a thermosetting yarn has appeared. Thermosetting yarn knitted hat, by using a conventional fiber yarn and thermosetting yarn together to manufacture a knitted hat, some of the disadvantages of the conventional knitted hat were also solved. In the case of the hat using thermosetting yarn, since the hat was hardened in a high-temperature environment, there was an advantage that it was not easily crushed even when some force was applied externally. Due to these advantages, they have been used for high-quality hats such as golf caps.

However, the hat using the thermosetting yarn has a disadvantage of the high price of the thermosetting yarn, and it cannot be practical as a common hat as the final product is expensive.

In addition, when the external force applied to the hat was weak, the hat using the thermosetting yarn could preserve its original shape. However, the hat manufactured using the thermosetting yarn could not recover the original shape when the external force was strong and the hat was deformed permanently or broken, being one of disadvantages of the hat manufactured using the thermosetting yarn.

In other words, the conventional hat using thermosetting yarn was expensive and had the advantage of a high-quality hat, but the messed up appearance could not be restored, and the fatal disadvantage of not being able to use the hat like the original hat has not been resolved by now.

Consequently, the conventional knitted hats hardly retain the original shape by the fibers, so if they are deformed by an external force applied, they are not able to restore original shape and the disadvantages are not solved yet.

Prior art documents studied by the inventor until now are as follows:

PATENT DOCUMENTS

-   Korean Patent registration No. 10-0587131 “Cap having     dual-structured crown”; -   Korean Patent registration No. 10-0661283 “Manufacturing method of     cap and cap thereof”; -   Korean Patent registration No. 20-0206265 “A cap visor for natural     matter summer”; -   Korean Patent registration No. 20-0350850 “Cap of brim made of     knit”.

SUMMARY OF THE INVENTION

The object of the present invention is to provide a hat capable of restoring the original shape from the deformed appearance by an external force. The object of the present invention is achieved by a hat capable of shape recovery after the deformation or damage due to external force by coating the surface of synthetic fiber yarns of the hat with mixtures from 100 parts by weight of the typical waterborne polyurethane, 0 to 400 parts by weight of water, 0.1 to 1.5 parts by weight of a crosslinking agent, and 0.1 to 3 parts by weight of clay powder (NaMMT); by curing the mixtures in a temperature range of 50° C. to 120° C. for crosslinking reactions via the cure of the polyurethane component; and by forming a thin polyurethane film on the surface of fabric or knitted fabric of the hat. In the present invention, preferably, the hat has been manufactured using a fabric woven with chemical fiber yarns such as nylon-6, polyester, acrylic, or a knitted hat with such chemical fiber yarn.

The hat according to the present invention is a cap-type hat or a knitted hat obtained by knitting by manufacturing apparatus. The surface of the synthetic fiber yarn of the hat undergoes treatments characterized by a coating process with the mixtures; a curing reaction process of the mixtures; and a forming thin film process formed on the surface of the fabric or the knit by chemical crosslinking reaction afterwards.

The product of crosslinking cure reaction of the thin polyurethane film provides a shape recovery that allows it to be restored to its original shape after the original shape of the crown of the cap-type hat or the knitted hat is deformed or damaged by an external force.

The method for manufacturing a hat according to the present invention is comprising the steps of: 1) preparing mixtures which are comprising of 100 parts by weight of the typical waterborne polyurethane, 0 to 400 parts by weight of water, and 0.1 to 1.5 parts by weight of a crosslinking agent for the waterborne polyurethane component; 2) coating the surface of fabric or knit for the hat with the mixtures; 3) curing the mixtures for the crosslinking in a temperature range of 50° C. to 120° C.; and 4) forming a thin polyurethane film on the surface of the fabric or knit of the hat for giving its own shape recovery power to the fabric or knitted fabric of the hat.

In the present invention, for the cap-type hat with fabric pieces, the crown may be cross-linked with the mixtures comprising the waterborne polyurethane component in a finished state, or a fabric or fabric piece is coated physically and cross-linked chemically with the waterborne polyurethane component, and then, a crown may be manufactured by sewing the cross-linked pieces of fabric.

In the present invention for the knitted hat, since the surface of the fiber yarn for the knitted hat is coated with a curing reaction product of a waterborne polyurethane component, the knitted hat does not undergo sagging and retains strength enough to maintain a desired original shape by recovering or restoring capability after deformation.

Therefore, the knitted hat according to the present invention, due to the reinforcement of the knitted material and the shape memory effect, has the advantages of maintaining the original shape even after deformations of the shape by the external force.

In addition, the present invention provides an environmentally friendly process for manufacturing a knitted hat of shape memory or cap-type hat by introducing physical interactions and chemical cross-linking reactions in the final step as shown in FIGS. 2 to 4 of the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a step-by-step chemical reaction scheme related to a representative embodiment of a method for producing a waterborne polyurethane dispersion (PUD) used in the present invention,

FIG. 2 is a chemical structural formula related to a representative example showing the curing reaction by the crosslinking agent of the waterborne polyurethane dispersion (PUD) used in the present invention,

FIG. 3 is a structural formula showing the interfacial hydrogen bonding between PUD and polyester fiber used in the present invention,

FIG. 4 is a structural formula showing the interfacial hydrogen bonding between PUD and the acrylic fiber used in the present invention, and

FIG. 5 is comparable photographs between a conventional knitted hat and a knitted hat according to the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Hereinafter, the present invention will be described more specifically and in detail. Specific numerical values or specific examples provided in the present invention are preferred embodiments of the present invention, and are only for explaining the technical idea of the present invention in more detail, and it is clear that the present invention is not limited thereto. In addition, in the specification of the present invention, detailed descriptions of parts that are known in the art and can be easily created by those of ordinary skill in the art will be omitted. In addition, in the specification of the present invention, the term “hat” includes a knitted hat and a cap-type hat, unless specifically described.

The present invention relates to a hat capable of restoring the original shape from the deformed appearance by an external force.

In general, the knitted hat is made in the form of a hat that can be worn on a user's head via knitting process from a chemical fiber yarn into a knitted fabric employing the hat manufacturing apparatus. On the other hand, cap-type hats are made by attaching the crown and brim via sewing of a number of pieces of fabrics produced by weaving chemical fiber yarns with warp and weft threads.

The hat according to the present invention is manufactured by knitting a synthetic fiber yarn into a knitted hat employing a conventional knitting hat manufacturing apparatus. It is preferable that the synthetic fibers forming the knitted hat include fiber yarns containing amide groups, ester groups, nitrile groups, and the like. On the other hand, in the case of the cap-type hat, the pieces of fabric forming the crown are made of the synthetic fiber yarns.

In the hat according to the present invention, chemical mixtures comprising a waterborne polyurethane component, water, and a crosslinking agent are coated on the surface of the synthetic fiber yarn constituting the hat. The hat is coated via a method of spraying a waterborne polyurethane dispersion on a knitted hat using compressed air, an immersing process for the knitted fabric in the aqueous polyurethane dispersion and then pulling it out, or a coating process using a printer with a roller and the like, and is not limited to the particular way.

Preferably, the mixtures further more comprise a clay powder.

The waterborne polyurethane dispersion in the mixtures forms physical or/and chemical bonds via hydrogen bonding or/and crosslinking at the interface and on the surface of the synthetic fiber yarns of knitted products after a thin polyurethane film formation on the surface of the knitted hat through the curing process. For example, when the synthetic fiber yarn constituting the hat contains nylon-6, crosslinking as shown in FIG. 2 is formed, whereas when the synthetic fiber yarn constituting the knitted product contains polyester and acrylic components, hydrogen bonds are formed as shown in FIGS. 3 and 4 . As crosslinking agents, multifunctional aziridine compounds and epoxy compounds are often used to form network structures through the reactions with the carboxylic acid moieties of waterborne polyurethane dispersions.

In this state, the waterborne polyurethane component is cured in the curing process to form a thin polyurethane film, and the thin cured polyurethane film functions to preserve the initial shape of the hat.

The hat according to the present invention includes a thin polyurethane film from the waterborne polyurethane dispersion on the surface of the fabric product, imparting a crosslinking reaction or hydrogen bonding between the waterborne polyurethane component and the fabric product by means of a crosslinking agent or physical interactions at the interface. The waterborne polyurethane component undergoes a physical and chemical crosslinking reaction with respect to the polyamide chemical fiber yarn of fabric products by a crosslinking agent. When the chemical fiber yarn is polyester or acrylic fiber, the cross-linked waterborne polyurethane is physically cross-linked through various hydrogen bonds. The crosslinking reaction can be achieved by maintaining the temperature in a range of about 50° C. to 120° C. for about 10 minutes to 30 minutes. When the crosslinking reaction is completed, the knitted product does not sag as in the prior art, but preserve the shape when the hat of the knitted hat is deformed by an externally applied force due to the thin polyurethane film formed on the surface of the knitted product.

Even when the hat according to the present invention is a cap type, since the fabric forming the crown contains a polyamide component, a polyester component, or an acrylic component, in the same manner as described above, the waterborne polyurethane component will be coupled to the crown fabrics.

In the hat according to the present invention, since the waterborne polyurethane component forms physical and chemical cross-linking with the synthetic fiber yarn of the knitted product at the thin film, the initial shape of the hat is preserved even after the damage due to deformation by an external force. When an external force is applied to the coated hat and deformation occurred in the shape, it can be restored to its original shape again. This is because the hat according to the present invention has a capability of shape memory, and when a user applies an external force to the deformed part during or after use of the hat, the recovering power allows restoring the original shape repeatedly.

In addition, the present invention provides a method for manufacturing a hat capable of restoring the original shape.

The method for manufacturing a hat according to the present invention may be performed after making a hat. The hat can be made in a conventional way. It includes a step of making a knitted hat employing a manufacturing apparatus to fabricate knitted products using a synthetic fiber yarn. The synthetic fiber yarn contains amide groups, ester groups, nitrile groups, and the like, and uses functional groups capable of physical and chemical crosslinking.

The method for manufacturing a hat according to the present invention includes a step (S 110) of preparing mixtures which comprise of 100 parts by weight of the typical waterborne polyurethane, 0 to 400 parts by weight of water, and 0.1 to 1.5 parts by weight of a crosslinking agent for the waterborne polyurethane component.

Waterborne polyurethane is an environmentally friendly polyurethane system developed to replace polyurethane coatings and adhesives dissolved in organic solvents. The present invention does not use conventional polyurethane in organic solvents, but uses a waterborne polyurethane dispersion based on consideration of environment-friendly characteristics as well as safety in toxicity to the human beings.

The method for producing the waterborne polyurethane dispersion may be performed in various ways.

For the production of the waterborne polyurethane dispersion, a glycolic acid compound such as dimethylol propionic acid (DMPA), which can stabilize the dispersion in water through self-emulsifying properties, is often included in the raw materials to manufacture waterborne polyurethane dispersion and incorporated through reactions for preparations of the waterborne polyurethane that does not use surfactant additionally. They can be used as environmentally friendly paints and adhesives. The polyurethane film formed after drying of such a waterborne polyurethane dispersion generally exhibits micro phase separation into a soft domain formed by a polyol and a hard domain formed by an isocyanate and a curing agent.

As a method for producing the waterborne polyurethane dispersion, a typical process is shown in FIG. 1 with a related chemical formula.

First, a polyurethane prepolymer in which both terminal hydroxyl groups of a diol component (polyester diol, polyether diol, polycarbonate diol, etc.) and glycolic acid such as dimethylol propionic acid (DMPA) are capped with isocyanate groups was prepared at 60° C. by reaction for about 3 hours. The molecular weight of the diol used here is mainly in the range of 1,000 g/mole to 3,000 g/mol. And as isocyanate, isophorone diisocyanate (IPDI), which is suitable for the process of reactive dispersion of polyurethane, is frequently used. When DMPA is used as the dihydroxy acid, the proportion in the polyurethane should be 3 to 6% by weight. After neutralizing the carboxylic acid moiety of the obtained polyurethane prepolymer with triethylene amine (TEA), water is added to disperse them in a colloidal state, and then ethylenediamine (EDA) is added as a chain extender to obtain a waterborne polyurethane dispersion.

The mixtures comprise of 0 to 400 parts by weight of water and 0.1 to 1.5 parts by weight of a crosslinking agent for the waterborne polyurethane component. The water dilutes the mixtures, and crosslinking agent promotes the polyurethane component in the mixtures to form crosslinking bonds with the various functional groups in the synthetic fiber yarn of the hat. As shown in FIG. 2 , when aziridine was used as a crosslinking agent and Nylon-6 was used as a synthetic fiber, it can be seen that a cross-linked structure was also formed through an interfacial reaction of the waterborne polyurethane component and the fiber. The cross-linking structure can be formed in the same way with the polymer component constituting the synthetic fiber.

Preferably, the mixtures further more comprise a clay powder. The mixtures comprise 0.1 to 3 parts by weight of the clay powder for the waterborne polyurethane component.

When the waterborne polyurethane dispersion system is prepared by diluting it with water, the clay powder may be used as an additive in order to improve dispersibility and elastic modulus. When the typical clay (NaMMT: Sodium montmorillonite) is properly dispersed in water, it is thickened, and there is an advantage that a thin and uniform waterborne polyurethane coating is achieved on the hat, and the mechanical strength is also increased. The most preferred simple coating method is the immersion deposition with the latter.

The method of manufacturing a hat according to the present invention includes a step (S 120) of coating the mixtures on the knitted hat or the woven fabric of the cap-type hat.

In the coating step (S 120) of the mixtures, it is important to prepare the waterborne polyurethane dispersion properly. In the present invention, the reason for using the waterborne polyurethane dispersion is as described above.

In the coating step (S 120) of the mixtures, the waterborne polyurethane dispersion in the above-described manner is coated together with the crosslinking agent on the knitted hat or the fabric of the cap-type hat. The coating method is not limited in a particular way. The waterborne polyurethane dispersion may be diluted in water and sprayed on the surface of the knitted hat, coated by a printing method, or immersed in an aqueous solution of the polyurethane dispersion and then removed.

In the case of the cap-type hat, the fabric forming the crown is coated with the waterborne polyurethane dispersion, and after the curing reactions are completed, the fabric can be cut and sewn to make a crown. The crown may be coated also with waterborne polyurethane dispersion after the crown of hat is prepared by sewing pieces of fabrics.

Preferably the method for manufacturing a hat according to the present invention includes a step (S 130) of making a desired temporary shape of a knit hat by putting it on a mold to maintain the shape of the hat before the cure of the waterborne polyurethane dispersion coated onto the hat.

The step to maintain the shape (S 130) of the knit hat may be performed using a conventional molding frame, which is well described in Korean Patent Registration No. 10-0661283 belonging to the prior art.

The method of manufacturing a hat according to the present invention comprises a step (S 140) of curing the mixtures for a crosslinking reaction in a temperature range of 50° C. to 120° C. for 10 minutes to 30 minutes.

In the curing step (S 140) of the hat, the initial shape of the hat is maintained using the molding frame, and physical and chemical crosslinking between the chemical fiber yarn of the knitted product and the polyurethane component in a high temperature environment is carried out during the curing. In the manufacturing method of the present invention, a simple coating of the surface of the hat is not good enough, but curing needs to induce physical and chemical bonding between the components of the fabric product and the components of the coating material to implement a strong bonding with each other to impart shape memory capability.

The crosslinking reactions undergoing in the curing step (S140) of the hat are carried out, in the state of maintaining the original shape, by keeping the hat in a temperature range of 50° C. to 120° C., for 10 minutes to 30 minutes. In the above temperature range, since the synthetic fiber yarn contains functional groups capable of physical and chemical crosslinking reactions such as amide groups, ester groups, nitrile groups, and acrylic groups, the waterborne polyurethane component undergoes various hydrogen bonds as well as crosslinking reactions. Crosslinking reactions occur between the waterborne polyurethane components and the fibers of hat.

In this curing step (S 140), a hot air drying oven may be used in order to rapidly proceed with the reaction.

As shown in FIG. 2 , when aziridine was used as a crosslinking agent and Nylon-6 was used as a synthetic fiber, it can be seen that a crosslinked structure was also formed through an interfacial reaction of the waterborne polyurethane component and the fiber. The cross-linking structure can be formed in the same way with the polymer component constituting the synthetic fiber.

Meanwhile, FIG. 3 shows a structural formula in which the waterborne polyurethane component exhibits hydrogen bonding with the polyester fiber.

In addition, FIG. 4 is a chemical structural formula showing that the waterborne polyurethane component exhibits hydrogen bonds with acrylic fiber at the interface.

The method for manufacturing a hat according to the present invention comprises a step (S 150) of forming a thin polyurethane film on the surface of the fabric or knit for the hat for giving its own shape recovery power to the fabric or knitted fabric of the hat.

Through the forming process, the waterborne polyurethane dispersion forms a thin film on the surface of the fabric, and the thin film maintains the shape of the hat. In addition, these waterborne polyurethane coated hats have the advantage of showing a shape memory effects even after washing.

In the hat according to the present invention, since the waterborne polyurethane component forms physical and chemical cross-linking with the synthetic fiber yarn of the hat at the thin film, the initial shape of the hat is preserved even if an external force is applied to the hat. When an external force is applied to the coated hat and deformation occurred in the shape, it can be restored to its original shape again because of a capability of shape recovery.

FIG. 5 illustrates the appearance of a conventional knitted hat a knitted hat according to the present invention.

Hereinafter, the present invention will be described in more detail through specific examples. However, in the patent application of the present invention, for convenience of explanation, it is clarified in advance that only a knitted hat using a knitted fabric is exemplified.

Example 1

For coating the knitted cap, a waterborne polyurethane dispersion (PUD 35) of solid content of 35% synthesized using a diol containing a carboxyl group such as dimethylol propionic acid was used. 1.232 parts by weight of an aziridine compound, trimethylolpropane tris(2-methyl-1-aziridinepropionate), undergoing chemical crosslinking with carboxyl acid groups of PUD during the drying process was incorporated into the waterborne polyurethane dispersion system.

A cap made by a conventional knitting process employing a manufacturing apparatus was immersed in the waterborne polyurethane dispersion system, and then taken out, and put on a mold for the typical shape of hat where the aqueous solution did not flow down during the coating and curing of a hat on the mold.

Hot air of 90° C. was applied for 15 minutes in a chamber for drying and curing of the polyurethane components on the surface of fiber yarns of hat on the mold.

The finished knitted hat was taken out from the drying chamber and examined the texture of knitted hat for the evaluation of the product. The results are given in Table 1.

Example 2

For 100 parts by weight of PUD 35, 100 parts by weight of water was added and 0.616 parts by weight of the crosslinking agent was added, and the rest were the same in Example 1.

The finished knitted hat was taken out from the drying chamber and examined the texture of knitted hat for the evaluation of the product. The results are given in Table 1.

Example 3

For 100 parts by weight of PUD 35, 300 parts by weight of water was added and 0.308 parts by weight of the crosslinking agent was added, and the rest were the same in Example 1.

The finished knitted hat was taken out from the drying chamber and examined the texture of knitted hat for the evaluation of the product. The results are given in Table 1.

Example 4

For 100 parts by weight of PUD 35, 400 parts by weight of water was added and 0.123 parts by weight of the crosslinking agent was added, and the rest were the same in Example 1.

The finished knitted hat was taken out from the drying chamber and examined the texture of knitted hat for the evaluation of the product. The results are given in Table 1.

TABLE 1 Example Example Example Example Constituent 1 2 3 4 PUD 35 100 100 100 100 Water 0 100 300 400 Aziridine cross-linker 1.232 0.616 0.308 0.123 Evaluation Texture AAA AAAA AAAA AAA Shape AAAAA AAAA AAAA AAA recovery Evaluation: Good (AAA); Very good (AAAA); Excellent (AAAAA)

According to Example 1, the shape recovery of the hat coated with PUD 35 without dilution with water was excellent and the texture of the hat was reasonably good. Texture of the hat coated with PUD diluted with water in the range of 100 phr and 300 phr by weight could be improved while the shape retention of the hat was weaken slightly. Further dilution of PUD with water more than 400 phr by weight for the coating of knitted hat resulted in the unsatisfactory texture and shape recovery of the hat.

Example 5

1.050 parts by weight of clay powder (NaMMT) was added to the recipe of Example 1 and the rest of the processes were the same.

The finished knitted hat was taken out from the drying chamber and examined the texture of knitted hat for the evaluation of the product. The results are given in Table 2.

Example 6

0.525 parts by weight of clay powder (NaMMT) was added to the recipe of Example 2 and the rest of the processes were the same.

The finished knitted hat was taken out from the drying chamber and examined the texture of knitted hat for the evaluation of the product. The results are given in Table 2.

Example 7

0.263 parts by weight of clay powder (NaMMT) was added to the recipe of Example 3 and the rest of the processes were the same.

The finished knitted hat was taken out from the drying chamber and examined the texture of knitted hat for the evaluation of the product. The results are given in Table 2.

Example 8

0.105 parts by weight of clay powder (NaMMT) was added to the recipe of Example 4 and the rest of the processes were the same.

The finished knitted hat was taken out from the drying chamber and examined the texture of knitted hat for the evaluation of the product. The results are given in Table 2.

TABLE 2 Example Example Example Example Constituent 5 6 7 8 PUD 35 100 100 100 100 Water 0 100 300 400 Aziridine crosslinker 1.232 0.616 0.308 0.123 NaMMT 1.050 0.525 0.263 0.105 Evaluation Texture AAA AAA AAAA AAAAA Shape AAAAA AAAAA AAAAA AAAAA recovery Evaluation: Good (AAA); Very good (AAAA); Excellent (AAAAA)

According to Examples 5 to 8, it was confirmed that, the adding the clay powder into the PUD systems resulted in the improvement of texture and the shape retention capability. In addition, it was found that when the clay powder (NaMMT) was added to diluted PUD systems for the coating of the hat, the texture and the shape recovering capability were excellent due to the uniformly coated polyurethane component.

Although the examples were given with a knitted hat, this is a description of the most representative example. It is natural that the shape recovering capability of a hat can be imparted to the sports hat comprising a fabric crown in the same way as in the knitted hat.

In the above, the hat having excellent circular shape retention and a method for manufacturing the same according to the present invention have been specifically described, but this is only a description of the most preferred embodiment of the present invention, and the present invention is not limited thereto and the scope is determined and limited by the appended claims.

In addition, it is clear that any person skilled in the art can make various modifications and imitations according to the description of the specification of the present invention, but this also does not depart from the scope of the present invention. 

What is claimed is:
 1. A hat capable of shape recovery after the deformation or damage due to external force by coating the surface of synthetic fiber yarns of the hat with mixtures comprising 100 parts by weight of the typical waterborne polyurethane, 0 to 400 parts by weight of water, 0.1 to 1.5 parts by weight of a crosslinking agent, and 0.1 to 3 parts by weight of clay powder (NaMMT); by curing the mixtures in a temperature range of 50° C. to 120° C. for crosslinking reactions via the cure of the waterborne polyurethane component; and by forming a thin polyurethane film on the surface of fabric or knitted fabric of the hat.
 2. The hat as claimed in claim 1, wherein the crosslinking reactions proceed between the waterborne polyurethane component and an amide group, an ester group, an acrylic group, or a nitrile group of the synthetic fiber yarns constituting the hat.
 3. The hat as claimed in claim 1, wherein the polyurethane film gives its own shape recovery power to the fabric or knitted fabric of the hat.
 4. A method for manufacturing cap-type or knitted hat for the user's head, capable of shape recovery after the deformation or damage due to external force, comprising the steps of: 1) preparing mixtures comprising 100 parts by weight of the typical waterborne polyurethane, 0 to 400 parts by weight of water, and 0.1 to 1.5 parts by weight of a crosslinking agent for the waterborne polyurethane component; 2) coating the surface of fabric or knitted fabric for the hat with the mixtures; 3) curing the mixtures for crosslinking reactions in a temperature range of 50° C. to 120° C.; and 4) forming a thin polyurethane film on the surface of the fabric or knitted fabric for the hat for giving its own shape recovery power to the hat.
 5. The method for manufacturing the hat claimed as in claim 4, wherein the mixtures further comprise 0.1 to 3 parts by weight of clay powder (NaMMT) for the waterborne polyurethane component. 